Riveting apparatus

ABSTRACT

Riveting apparatus is disclosed including a vertically disposed mandrel upon which is supported a supply of rivets. The forward end of the mandrel extends through nose jaws which are provided with abutment surfaces for supporting the leading rivet to be set. Pulling jaws are provided for gripping the mandrel and reciprocate the same in a forward and rearward direction, and latch means for preventing the rearward movement of the rivets along the mandrel. A resilient lever is secured to one of the pulling jaws for lifting and supporting the column of rivets to a position whereby the leading rivet is positioned at the rivet setting station immediately rearwardly of the mandrel head.

United States Patent Sheffield et al. July 1, 1975 [54] RIVETING APPARATUS 3,557,597 11971 geslop 72 391 [75] Inventors: David J Sheffield St Albans, 3,717,023 [i973 rosser 72/39l Hertfordshire; Paul Edward Prosser, Hemel Hempstead; Primary Examiner-C. W. Lanham Bernard William Char-man, Assistant ExaminerGene P. Crosby Weybridge, all of England Attorney, Agent, or Firm-Oblon, Fisher, Spivak,

M C] ll d & M [73] Assignee: Aer-pat A.G., Switzerland c e an aler [22] Filed: July 10, 1974 211 Appl. No.: 487,157 [57] ABSTRACT Related s Application Data Riveting apparatus is disiloslefl including a vertically [631 of 1972' through nose jaws which are provided with abutment 30 F A P 1 D ta surfaces for supporting the leading rivet to be set. i l M :11: Uf s y a 7 7 Pulling jaws are provided for gripping the mandrel and T 27 l 73 i l 8/ l reciprocate the same in a forward and rearward direc- Juy 9 mted Kmg om 35856/73 tion, and latch means for preventing the rearward movement of the rivets along the mandrel. A resilient 5 lever is secured to one of the pulling jaws for lifting {58] 527/55 and supporting the column of rivets to a position 0 are 219/243 whereby the leading rivet is positioned at the rivet setting station immediately rearwardly of the mandrel [56] References Cited head UNITED STATES PATENTS 5 Claims, 7 Drawing Figures 2,340,066 1/1944 Lee 72/39l SHEET FIG. i

FIG. 3

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P 0% w H/ RIVETING APPARATUS CROSS REFERENCE TO RELATED APPLICATION This is a continuation-in-part of application Ser. No. 257,200, now US. Pat. No. 3,828,603., filed May 26, 1972.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to riveting apparatus and more particularly to riveting apparatus which is capable of compensating for varying lengths of a supply of rivets supported upon a mandrel of the riveting apparatus due to manufacturing tolerances.

2. Description of the Prior Art Due to manufacturing tolerances, the lengths of tubular rivets sometimes differ slightly from one to another and this leads to small but significant variations in the length of a columnar supply of rivets supported within riveting apparatus of the kind referred to. It is therefore necessary to insure that the distance between the head of the mandrel and the pulling jaws is at least as great as the greatest length of the column of rivets to be accommodated upon this region of the mandrel. Usually, however, the length of the column is shorter than this distance with the result that the mandrel projects excessively beyond the leading rivet of the column. This a disadvantage when a rivet is to be set within a blind hole of a workpiece because the blind hole has to made deep enough so as to receive not only the rivet but also the projecting part of the mandrel.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide improved riveting apparatus.

Another object of the present invention is to provide riveting apparatus which will overcome the abovenoted disadvantages.

Still another object of the present invention is to provide riveting apparatus which includes means which is operative to advance the column of rivets up to the head of the mandrel and which is therefore capable of compensating for variations in the length of the column of rivets.

Yet another object of the present invention is to provide apparatus of the kind defined wherein there is provided yieldable means for advancing the column of rivets forwardly along the mandrel when the mandrel is moved forwardly by means of pulling jaws, the yieldable means comprising a lever mounted for pivotal movement in response to movement between the pulling jaws and a relatively fixed part of the riveting apparatus, and which may be formed of a flexible resilient mate rial such as spring steel so as to yield when the column of rivets abuts the head of the mandrel.

The foregoing objects are achieved according to the present invention through the provision of riveting apparatus having an elongate mandrel arranged substantially vertically, and including a stem adapted to carry a plurality of tubular rivets forming a column of rivets thereon and an enlarged head at the forward end thereof, nose jaws through which the mandrel extends and which provide an abutment for supporting each of the rivets of the column in turn, the jaws and mandrel being relatively reciprocable in the lengthwise direction of the mandrel so as to provide a feed stroke during which the head of the mandrel is moved to a position forwardly of the jaws and the leading rivet of the column passes through the nose jaws which then close to provide an abutment rearwardly of the head of the leading rivet for a rivet setting stroke during which the mandrel moves rearwardly relative to the nose jaws so that the head of the mandrel is pulled entirely through the bore of the leading rivet supported by the nose jaws, pulling jaws arranged to grip the mandrel rearwardly of the column of rivets and to reciprocate the mandrel, the pulling jaws being retractable from the mandrel so as to permit tubular rivets to be fed forwardly along the stem of the mandrel so as to join the column of rivets, latch means for supporting the column of rivets forwardly of the pulling jaws when the pulling jaws are retracted from the mandrel, and a resilient lever secured to one of the pulling jaws for lifting the column of rivets to a position at which the leading rivet is immediately rearward of the mandrel head.

BRIEF DESCRIPTION OF THE DRAWINGS Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like or corresponding parts throughout the several views, and wherein:

FIGS. 1 to 4 are schematic front elevation views of a blind riveting machine constructed according to the present invention, showing the relative positions of the principal components of the machine in successive stages of operation;

FIGS. 5 and 6 are schematic side elevation views of the apparatus shown in FIGS. 1-4, showing the relative positions of the principal components of the machine in two other stages of operation intermediate those stages shown in FIGS. 3 and 4; and

FIG. 7 is a plan view of the lever component system of the machine.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The riveting machine of the present invention is intended for setting blind tubular rivets of the kind comprising a shank and an enlarged head at one end thereof, and having a bore extending through the head and shank. Such rivets are well known and are commercially available under the registered Trademark Chobert." The rivets are set by means of a mandrel having a stem upon which the rivets are disposed with a sliding fit, and an enlarged head at the forward end of the stern, each rivet being threaded onto the mandrel stem with the tail end of the rivet, that is, the end of the rivet shank remote from the rivet head disposed towards the head of the mandrel, whereupon the mandrel is then pulled rearwardly so as to draw the mandrel head through the rivet bore thereby expanding the shank of the rivet and setting the same.

The machine of the present invention is adapted to automatically serially supply the rivets to a rivet setting station and to set the rivets within a suitably apertured workpiece at the setting station from a position below the workpiece. Thus the mandrel is substantially vertical with its head uppermost, and the rivets are presented to the setting station with the head end down and the tail extending vertically upwards. A workpiece to be riveted is positioned so that the tail of the rivet projects into or through an aperture within the work' piece, whereupon the rivet is then set. A succeeding rivet is then automatically presented to the setting station for the next setting operation.

Referring now to the drawings, the riveting machine generally indicated by the reference character includes a mandrel generally indicated by the reference character I2 having an elongated stem 14 and a head 16 at one end thereof. the head end of the mandrel being regarded as the forward end while the other end is regarded as the rear end. The mandrel is mounted vertically with the head 16 uppermost, and is reciprocable along its axis in relation to a pair of nose jaws l8 and which are disposed upon opposite sides of the mandrel stem at a position adjacent to the head 16. The nose jaws l8 and 20 each present a forwardly facing abutment surface 22 and 24 adjacent to the mandrel and are resiliently urged towards a closed position by means not shown, in which these abutment surfaces normally cooperate to form an annular abutment means peripherally about the mandrel. When the mandrel is moved forwardly. the head 16 is spaced for wardly of the nose jaws, that is, above them by a distance atleast as great as the length of a rivet as shown more particularly in FIG. 4, and when the mandrel is moved to its rearward position, the head 16 is interposed between the jaws 18 and 20 so that the forward end of the mandrel is flush with or to the rear of the abutment surfaces 22 and 24 of the nose jaws, as is shown in FIG. 2.

The mandrel 12 is reciprocated by means of a pair of pulling jaws 26 and 28 which are disposed rearwardly of the nose jaws l8 and 20. The pulling jaws are movable between a closed position in which they cooperate to hold the mandrel and an open position in which they are disengaged from the mandrel so that rivets can move forwardly along the mandrel past the pulling jaws 26 and 28, the jaws 26 and 28 being reciprocable in the lengthwise direction of the mandrel. The movements of the pulling jaws are rather complex and will be discussed hereinafter, however it is noted that when the mandrel 12 is in its rearward position, the pulling jaws 26 and 28 disengage therefrom and do not retain the same in the rearward position. In order to accomplish such, when the mandrel is at its rearward position, it is engaged and held by means of detent 30 situated rearwardly of the pulling jaws 26 and 28, detent 30 comprising a ball 32 which is spring-biased by means of a compression spring 34 so as to engage a peripheral groove 36 formed within an area of the mandrel stem near the rear end thereof.

A pair of rivet locating jaws 38 and 40 are also disposed upon opposite sides of the mandrel axis at a position immediately forward of the detent 30 but generally rearwardly of the rear end of the mandrel when the mandrel is in its forward position as seen in FIG. 4, the locating jaws being able to open and close in synchronism with the opening and closing of the pulling jaws 26 and 28.

A rivet locating plunger 59, as shown in FIGS. 5 and 6, is reciprocable at right angles to the mandrel axis so as to serially deliver rivets one at a time from rivet supply means, not shown, into position between the closed locating jaws 38 and 40 when the mandrel is in its forward position. A rivet thus delivered is held rearwardly of the mandrel by means of the locating jaws with its bore aligned with the mandrel and with the tail end of the rivet disposed towards the nose jaws l8 and 20.

A jet 42 is disposed upon the axis of the mandrel at a position which is to the rear of the rear end of the mandrel when the mandrel is in its rearward position as seen in FIG. 2, and is adapted to direct a stream of air or other gas forwardly along the mandrel, the jet 42 being connected through means of a conduit, not shown, to a source of pressurized air or other gas.

A latch 44 for supporting the column of rivets rearwardly of the nose jaws l8 and 20 is mounted for piv otal movement towards and away from the mandrel as seen in FIGS. 5 and 6, and is resiliently urged by means not shown, into a position close to or engaging the mandrel. The latch is pivotally movable away from the mandrel so as to allow rivets to move forwardly along the mandrel and is resiliently biased toward the mandrel so as to prevent rivets from moving rearwardly along the mandrel. Thus a plurality of rivets may be fed along the mandrel past the latch so as to form and maintain a columnar supply of rivets between the latch 44 and the nose jaws l8 and 20. As shown in FIG. 1, the mandrel is at its rearward position and extends through four rivets of which three rivets 46, 48 and 50 form a column which is supported by means of the latch 44, the fourth rivet 52 being located between the locating jaws 38 and 40.

The yieldable means for advancing the column of rivets forwardly along the mandrel when the mandrel is moved forwardly by means of the pulling jaws 26 and 28 comprises a lever generally indicated by the reference character 60 which is mounted upon the pulling jaw 26 by means of a mounting block 54. As shown in FIG. 7, the lever 60 is formed of a length of spring steel wire deformed into a substantially rectangular configuration so as to have a beam 62, lever ends 64 and 66 disposed at opposite ends of the beam 62, and a stay 68 which extends parallel to the beam 62 from the lever end 66 towards the lever end 64. The free end of the stay 68 is directed inwardly towards the beam 62 so as to form a journal 70.

The block 54 therefore provides a pivotal bearing for the lever 60 in the form of a through bore 72 one end of which receives the journal of the lever 60 and the other end of which receives a pivot pin 76 having a slotted head 78 through which the beam 62 of the lever 60 passes. Block 54 is mounted upon the forwardly disposed surface of the pulling jaw 26 and supports the lever 60 for pivotal movement about a horizontal axis which extends parallel to the lever ends 64 and 66 and which intersects the beam 62 at a position intermediate between its ends and somewhat nearer to the lever end 66 so that the lever end 64 is normally weighted downwardly. The lever 60 is mounted such that when the pulling jaws 26 and 28 are closed together so as to grip the mandrel 12, the lever end 64 is adjacent to the mandrel and directly below the column of rivets, the lever end 66 being of course remote from the mandrel 12.

The riveting machine also includes a frame having an upper cross member 82 disposed forwardly of the forward limit of travel of the pulling jaws 26 and 28 as seen in FIG. 4, cross member 82 serving as a stop which, when the pulling jaws are moving forwardly and approaching the forward limit of their travel, is engaged by and prevents further forward movement of the lever end 66. When the lever end 66 has engaged the stop 82, further forward movement of the pulling jaw causes the lever 60 to pivot so that the lever end 64 moves forwardly ahead of the pulling jaws.

The manner in which the riveting machine operates is generally similar to that described in our co-pending patent application referred to above and in particular the operation of the machine is under the control of a logical pneumatic circuit which causes the machine to perform a cycle of operations commencing with the condition shown in FIG. 4 and which is completed by the return of the machine to that condition. In order to illustrate the operation of the novel features according to the invention, it is convenient to refer first to the condition of the machine as illustrated in FIG. 1 in which the mandrel is in its rearmost position and the forward end thereof is a short distance to the rear of the abutment surfaces of the nose jaws 18 and 20, the detent 30 being engaged within the peripheral groove 36 of the mandrel stem 14. A column of rivets 46, 48, 50 disposed upon the mandrel stem is supported by means of the latch 44 and the pulling jaws 26 and 28 are spaced rearwardly of the latch by a distance slightly greater than the length of a rivet. Another rivet 52 located between the locating jaws 38 and 40 is disposed upon the mandrel stem rearwardly of the pulling jaws 26 and 28 which are still in the course of their rearward movement and are commencing to retract from the mandrel 12 so that the mandrel is no longer being moved rearwardly.

The rearward and opening movements of the pulling jaws 26 and 28 continue until the jaws reach their rearmost position in which they are fully open and simultaneously the locating jaws 38 and 40 also open. A stream of air or other gas is then delivered through the jet 42 and upon engaging the head of the rivet 52 drives it forwardly past the pulling jaws 26 and 28 until the rivet abuts the rearward side of the latch 44 as shown in FIG. 2. The stream of air is sustained so as to maintain the fed rivet 52 in abutment with the latch, whereupon the pulling jaws now begin to move forwardly and to close progressively. The jaws eventually close upon the mandrel 12 at a position just below the head of the rivet 52 with the lever end 62 interposed between the jaws 26 and 28 and the head of the rivet 52 as shown in FIG. 3. The pulling jaws continue to move forwardly, gripping the mandrel l2 and in so doing, urge the rivet 52 forwardly past the latch 44 which resiliently yields so as to permit the rivet 52 and the jaws to pass thereby as seen in FIG. 5. Although the column of rivets 46, 48, 50, 52 is somewhat shorter than the distance between the pulling jaws 26 and 28 and the head of the mandrel, it will be seen from FIG. 6 that the leading rivet 46 resiliently opens, and passes through, the nose jaws l8 and 20.

The pulling jaws 26 and 28 now approach the forward limit of their travel and the lever end 66 of the lever 60 abuts the stop means provided by the cross member 82 of the machine frame. As the pulling jaws complete their forward movement, the lever 60 is caused to pivot about its horizontal pivotal axis so that the lever end 64 lifts the column of rivets ahead of the pulling jaws 26 and 28 until the leading rivet 46 abuts the head 16 of the mandrel l2 and the nose jaws l8 and 20 close behind the head of the leading rivet 46. It will be appreciated that the distance traversed in the forward direction by the lever end 64 is arranged so as to be sufficient to lift a column of rivets of predetermined length into abutment with the head of the mandrel. If

however, due to manufacturing tolerances the length of the column of rivets is greater than this predetermined length the lever 60 will begin to bend as soon as the leading rivet of the column abuts the head of the mandrel.

Consequently, when the pulling jaws 26 and 28 and the mandrel l2 reach the forward limit of their travel, the leading rivet 46 is disposed forwardly of the nose jaws l8 and 20 which are closed about the stem of the next succeeding rivet 48 and below the head of the leading rivet 46. In this condition the machine is ready to be actuated in order to set the leading rivet 46 which is achieved by the rearward movement of the pulling jaws 26 and 28 while gripping the mandrel 12 whereby the head 16 of the mandrel 12 is pulled through the leading rivet 46 supported by the nose jaws l8 and 20. During such operation, another rivet 56 has been fed into position between the locating jaws 38 and 40 by means of the rivet locating plunger 59 so that the machine is in the condition shown in FIG. 4.

Obviously, many changes and modifications of the present invention are possible in light of the above teachings. It is to be understood therefore, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Blind riveting apparatus comprising:

a mandrel including an elongated stern and a head at one end thereof;

a plurality of rivets slidably supported upon said mandrel, each of said rivets having a head end and a tail end;

abutment means for supporting the leading one of said rivets at a rivet setting station;

gripping means for moving said mandrel and said rivets toward said rivet setting station; and

means for advancing said rivets relative to said man drel whereby said leading rivet is advanced to a position adjacent said rivet setting station at which position the tail end of said leading rivet abuts said head end of said mandrel while the head end of said leading rivet is adjacent to said abutment means and is adapted to engage said abutment means during a rivet setting operation.

2. Blind riveting apparatus as set forth in claim 1 wherein said means for advancing said rivets is interposed between said rivets and said gripping means.

3. Blind riveting apparatus as set forth in claim I wherein said means for advancing said rivets is mounted upon said gripping means.

4. Blind riveting apparatus as set forth in claim 1 wherein said means for advancing said rivets comprises:

a flexible lever pivotally mounted upon said gripping means and inclined relative to the longitudinal axis of said mandrel,

the lower end of said lever being interposed between said rivets and said gripping means while the upper end of said lever is interposed between said gripping means and a portion of the framework of said apparatus,

whereupon said mandrel and said rivets being moved toward said rivet setting station by said gripping means, said upper end of said lever will abut said portion of said framework so as to pivotally move said lower end of said lever into abutment with said rivets and advance the same relative to said mandrel and into abutment with said head end of said mandrel.

5. Blind riveting apparatus as set forth in claim 4,

wherein said flexible lever is made of spring steel. 

1. Blind riveting apparatus comprising: a mandrel including an elongated stem and a head at one end thereof; a plurality of rivets slidably supported upon said mandrel, each of said rivets having a head end and a tail end; abutment meAns for supporting the leading one of said rivets at a rivet setting station; gripping means for moving said mandrel and said rivets toward said rivet setting station; and means for advancing said rivets relative to said mandrel whereby said leading rivet is advanced to a position adjacent said rivet setting station at which position the tail end of said leading rivet abuts said head end of said mandrel while the head end of said leading rivet is adjacent to said abutment means and is adapted to engage said abutment means during a rivet setting operation.
 2. Blind riveting apparatus as set forth in claim 1 wherein said means for advancing said rivets is interposed between said rivets and said gripping means.
 3. Blind riveting apparatus as set forth in claim 1 wherein said means for advancing said rivets is mounted upon said gripping means.
 4. Blind riveting apparatus as set forth in claim 1 wherein said means for advancing said rivets comprises: a flexible lever pivotally mounted upon said gripping means and inclined relative to the longitudinal axis of said mandrel, the lower end of said lever being interposed between said rivets and said gripping means while the upper end of said lever is interposed between said gripping means and a portion of the framework of said apparatus, whereupon said mandrel and said rivets being moved toward said rivet setting station by said gripping means, said upper end of said lever will abut said portion of said framework so as to pivotally move said lower end of said lever into abutment with said rivets and advance the same relative to said mandrel and into abutment with said head end of said mandrel.
 5. Blind riveting apparatus as set forth in claim 4, wherein said flexible lever is made of spring steel. 